Absorbant laminates and method of making same

Abstract

Absorbent laminates include an oriented, fluid-pervious plastic substrate bonded to a nonwoven absorbent member. The nonwoven absorbent member includes bi-component fibers having a heat-softenable outer skin, said heat-softenable outer skin being heat-softenable at a temperature lower than the melting point and shrinking point of the oriented plastic substrate to provide a binder component for the laminate. A fluid-pervious plastic substrate can be adhered to one or both surfaces of the nonwoven absorbent member through bi-component fibers of the nonwoven absorbent member. In absorbent laminates including opposed fluid-pervious outer plastic substrates marginal edges of the laminate can be compression sealed through the bi-component fibers in the intermediate nonwoven absorbent member to seal the edges against the escape of fibers from the laminate. Methods of forming absorbent laminates of this invention also form a part of the present invention.

What is claimed as the invention is: 
     
       1. An absorbent laminate comprising an oriented, fluid-pervious plastic substrate having a melting point and a shrinking point, said plastic substrate being bonded to a nonwoven absorbent member, said nonwoven absorbent member including bi-component fibers having a heat-softenable outer skin, said heat-softenable outer skin being heat-softenable at a temperature lower than the melting point and the shrinking point of the oriented plastic substrate to provide a binder component for the laminate. 
     
     
       2. The absorbent laminate of claim 1, wherein said nonwoven absorbent member is a dry-formed member including said bi-component fibers intermingled with other fibers. 
     
     
       3. The absorbent laminate of claim 2, wherein the outer skin of the bi-component fibers is a polyolefin and said other fibers are polyolefin fibers. 
     
     
       4. The absorbent laminate of claim 1, wherein said oriented plastic substrate is permeable to liquid. 
     
     
       5. The absorbent laminate of claim 1, wherein said oriented plastic substrate is an apertured web. 
     
     
       6. The absorbent laminate of claim 1, wherein said oriented plastic substrate is a polyolefin substrate. 
     
     
       7. The absorbent laminate of claim 6, wherein the outer skin of the bi-component fibers is a polyolefin. 
     
     
       8. The absorbent laminate of claim 6, wherein said nonwoven absorbent member includes said bi-component fibers intermingled with other fibers. 
     
     
       9. The absorbent laminate of claim 8, wherein the outer skin of the bi-component fibers is a polyolefin and said other fibers are polyolefin fibers. 
     
     
       10. The absorbent laminate of claim 6, wherein said polyolefin substrate is pervious to liquid. 
     
     
       11. The absorbent laminate of claim 6, wherein said polyolefin substrate comprises polyethylene. 
     
     
       12. The absorbent laminate of claim 6, wherein said polyolefin substrate is an apertured substrate comprising polyethylene. 
     
     
       13. The absorbent laminate of claim 12, wherein the outer skin of the bi-component fibers is a polyolefin. 
     
     
       14. The absorbent laminate of claim 12, wherein said nonwoven absorbent member includes said bi-component fibers intermingled with other fibers. 
     
     
       15. The absorbent laminate of claim 14, wherein the outer skin of the bi-component fibers is a polyolefin and said other fibers are polyolefin fibers. 
     
     
       16. A method of forming an absorbent laminate comprising an oriented, fluid pervious plastic substrate bonded to a nonwoven absorbent member, said nonwoven absorbent member including bi-component fibers having a heat-softenable outer skin thereon, said method including the steps of: forming an array of fibers including said bi-component fibers therein,   heating the array of fibers to a temperature for softening the outer skin of the bi-component fibers to a sufficient degree for bonding said array of fibers together to form said nonwoven absorbent member and for bonding said nonwoven absorbent member to the oriented plastic substrate, wherein said temperature for bonding the fibers together and for bonding the absorbent member to the oriented plastic substrate is below the temperature at which the oriented plastic substrate will shrink or otherwise become distorted,   positioning said array of fibers contiguous to the plastic substrate, and   applying pressure to said array of fibers and plastic substrate after said array of fibers has been heated to said sufficient degree to thereby bond the array of fibers together into said nonwoven absorbent member and to bond the nonwoven absorbent member to the plastic substrate.   
     
     
       17. The method of claim 16, wherein the step of heating the array of fibers takes place after said positioning step. 
     
     
       18. The method of claim 16, wherein the step of heating the array of fibers takes place before said positioning step. 
     
     
       19. The method of claim 16, wherein the array of fibers is formed by mixing together said bi-component fibers and other fibers. 
     
     
       20. The method of claim 19, wherein said bi-component fibers include an outer skin comprising a polyolefin and said other fibers comprise polyolefin fibers. 
     
     
       21. The method of claim 16, wherein said array of fibers is formed as a multi-layer construction by positioning a thin layer comprising predominantly bi-component fibers in overlying relationship with one or more additional layers comprising a lower percentage of bi-component fibers than in said thin layer, said thin layer being disposed contiguous to the oriented plastic substrate to thereby bond the nonwoven material to said substrate through bi-component fibers of said thin layer. 
     
     
       22. The method of claim 21 wherein said thin layer is formed solely of bi-component fibers. 
     
     
       23. The method of claim 21, wherein said additional layers of fibers include from about 20% bi-component fibers to about 100% bi-component fibers. 
     
     
       24. A method of forming an absorbent laminate comprising a pair of oriented plastic substrates, at least one of said plastic substrates being fluid pervious, said substrates being bonded to opposed surfaces of a nonwoven absorbent member, said nonwoven absorbent member including bi-component fibers having a heat-softenable outer skin thereon, said method including the steps of: forming an array of fibers including said bi-component fibers therein,   heating the array of fibers to a temperature for softening the outer skin of the bi-component fibers to a sufficient degree for bonding said array of fibers together to form said nonwoven absorbent member and for bonding said nonwoven absorbent member to each one of the pair oriented plastic substrates, wherein said temperature for bonding the fibers together and for bonding the absorbent member to the pair of oriented plastic substrates is below the temperature at which the oriented plastic substrates will shrink or otherwise become distorted,   positioning said array of fibers contiguous to an between the pair of plastic substrates, and   applying pressure to said array of fibers and plastic substrates after said array of fibers has been heated to said sufficient degree to thereby bond the array of fibers together into said nonwoven absorbent member and to bond the nonwoven absorbent member to the plastic substrates.   
     
     
       25. The method of claim 24, wherein the step of heating the array of fibers takes place after said positioning step. 
     
     
       26. The method of claim 24, wherein the step of heating the array of fibers takes place before said positioning step. 
     
     
       27. The method of claim 24, wherein the array of fibers is formed by mixing together said bi-component fibers and other fibers. 
     
     
       28. The method of claim 27, wherein said bi-component fibers include an outer skin comprising a polyolefin and said other fibers comprise polyolefin fibers. 
     
     
       29. The method of claim 24, wherein said array of fibers is formed as a multi-layer construction by positioning outer thin layers comprising predominantly bi-component fibers in overlying relationship with one or more additional inner layers comprising a lower percentage of bi-component fibers than is in said thin outer layers. 
     
     
       30. The method of claim 29, wherein said thin outer layers are formed solely of bi-component fibers. 
     
     
       31. The method of claim 29, wherein said additional inner layers of fibers include from about 20% bi-component fibers to about 100% bi-component fibers. 
     
     
       32. The absorbent laminate of claim 1, wherein said bi-component fibers bond fibers of the nonwoven absorbent member together and bond the nonwoven absorbent member to the oriented plastic substrate. 
     
     
       33. The absorbent laminate of claim 1, wherein said nonwoven absorbent member is a needle-punched absorbent member. 
     
     
       34. The absorbent laminate of claim 1, wherein said nonwoven absorbent member includes a higher concentration, by weight, of bi-component fibers contiguous to the plastic substrate than in the interior of said nonwoven absorbent member. 
     
     
       35. An absorbent laminate comprising a multi-layer substrate bonded to a nonwoven absorbent member, one of said layers of said substrate being an oriented, fluid-pervious plastic film and the other of said layers being a low melt skin for bonding said multilayer substrate to said nonwoven absorbent member, said nonwoven absorbent member including bi-component fibers having a core and heat-softenable outer skin, said heat-softenable outer skin of said bi-component fibers having a melting point and softening point lower than the melting point and softening point of the core of the bi-component fibers and higher than the melting point and softening point of the low melting skin of the multilayer substrate, both said low melt skin of the substrate and the heat-softenable outer skin of the bi-component fibers comprising a binder for the absorbent laminate. 
     
     
       36. An absorbent laminate comprising outer oriented, fluid-pervious plastic substrates and an intermediate nonwoven absorbent member disposed between and bonded to said outer substrates, said nonwoven absorbent member including bi-component fibers having a heat-softenable outer skin bonding fibers of the nonwoven absorbent member together and bonding the nonwoven absorbent member to the oriented plastic substrates. 
     
     
       37. The absorbent laminate of claim 36 wherein said nonwoven absorbent member includes a higher concentration, by weight, of bi-component fibers at the surfaces of the nonwoven absorbent member contiguous to the oriented, fluid-pervious plastic substrates then in the interior of said nonwoven absorbent member. 
     
     
       38. An absorbent laminate comprising a facing layer adapted to be positioned against a person's skin, a backing layer adapted to be positioned remote from the skin, and a nonwoven absorbent member disposed between the facing layer and the backing layer, said facing layer being an oriented, fluid-pervious plastic substrate bonded to said nonwoven absorbent member, said backing layer being a liquid-impermeable substrate bonded to said nonwoven absorbent member, said nonwoven absorbent member including bi-component fibers having a heat-softenable outer skin for bonding said nonwoven absorbent member to both said facing layer and said backing layer. 
     
     
       39. The absorbent laminate of claim 38 including peripheral regions of said facing layer and said backing layer being secured together in compressed, sealed margins through bi-component fibers of the nonwoven absorbent member, said sealed margins providing a sealed barrier for preventing fibers of the nonwoven absorbent member from escaping from the laminate marginal areas.